Safety device for skip cars



May 28,- 1946. c. M. GUY

SAFETY DEVICE FOR SKIP CARS Filed July 2'7, 1945 2 Sheets-Sheet 1 FIG. 3-

hweizior. 674E155 M 60),

Patented May 28, 1946 SAFETY DEVICE FOR SKIP CARS Charles M. Guy, PittsburglI Pa., assignor to Carnegie-Illinois Steel Corporation Application July 27, 1945, Serial No. 607,341

2 Claims.

The present invention relates to improvements in means to prevent damage to a blast furnace structure and its related equipment by derailed skip cars, and is well suited for use on modern blast furnaces employing automatically controlled mechanical charging systems.

As is well known to those skilled in the art, the operation of modern blast furnaces involves the charging of burden materials such as coke, ore, and limestone, into the top of the furnace. This is accomplished by means of skip cars which ride up and down on a bridge-like inclined skipway extending to the top of the furnace from a charging station or skip pit below the bottom of the stock house. The burden materials are charged into skip cars at the skip pit, each skip car having a capacity of approximately 250 cubic feet. In a modern blast furnace the speed of the skip car is approximately from 300 to 500 feet per minute. Usually two skip cars are used, each car being connected by a wire rope of 1% inches" in diameter, running over sheaves to a skip drum driven by a motor located in a suitable skip hoist 7 control room. The skip cars alternately ride up and down the incline, the loaded car going up being counterbalanced in part by the empty car equipped with mechanical charging systems which are largely automatically controlled and hence do not require the constant attendance of an operator. Such derailments have occurred in the past, and in one instance resulted in extensive damage to the skipway bridge and furnace top structure, with resulting interference to blast furnace charging operations.

The present invention aims to provide means to prevent damage to the furnace structure or to the skipway, in the event of derailment of the skip car, by the provision of means to automatically actuate a motor control switch effective to stop the drive motor for the skip hoist drum upon derailment of the skip car.

The invention will be fully apparent from consideration of the following detailed disclosure and the accompanying drawings, and will be defined with particularity in the appended claims.

In the drawings:

Figure 1 is a simplified side elevation of a'blast furnace and skipway, diagrammatically showing which drives the skip hoist drum.

Referring in detail to the drawings, reference numeral 10 conventionally represents a blast furnace; l2 a loading station near the-base of the furnace, where the skip cars are adapted to be charged with burden materials such as ore, coke, and limestone, in any suitable manner forming no part of the present invention. The furnace is equipped with a conventional skipway indicated generally at M. This is a known form of bridgelike structure built up of suitable rolled steel sections. This bridge structure includes a multiplicityof cross beams [6 such as shown in Figure 3,'supporting rails 18 for two parallel tracks alon which are adapted to travel skip cars 20 and 22. Usually the skipway haulage cables are so connected and arranged that when one loaded skip car is ascending, the other empty car is descend ing, Thus the empty car partly counterbalances the loaded car. As shown, for example, a single hoist drum 24 has cables 26 and 28 wrapped thereon in opposite directions, one cable 26' being connected to the skip car 20 and the other cable 28 being connected to the skip car 22. These cables run over suitable guide sheaves 30 carried in suitable bearings on fixed frame members forming part of the overhead blast furnace strpc ture. When the hoist drum rotates in one direction, one cable will be wound on the drum and the other cable will be paid off, thus causing one skip car to ascend and the other to descend. A drive motor 32 is operatively connected in any suitable manner with the hoist drum 24. This motor is connected in a suitable power circuit,

sections are equipped with steel flanges at each by a bolt 44. The flanges 38 and 40 are detach- 5 ably secured to one another by through-bolts 46, thus permitting easy installation of the pipe sec- 1 tlons. The several pipe sections and flanges as thus coupled'together jointly form an actuatin 1 member for the switch 34. V y

secured to suitable, parts of the skipway structure I providea plurality of brackets 48 having 1 bearing portions 50 equipped with suitable brass 1 bushings for slidablyrguiding the pipe sections; 1

1 Springs 52 surrounding the pipe sections are interposed between the flanges 38 and bearings 50.-

One of the pipe sections has a pin 51 secured I thereto engaging a forked end '53 of an arm 54 1 1 which when rocked is adapted to actuate'th'e switch '34. The several bracketsi48 are located 1 between the parallel tracks traversed by the skip j cars 20 and 22. As thus arranged, it is apparent i thatin the event either'skip' car is derailed, one

i of the wheels 56 ofthe derailed skip car will i 1 strike one of the flanges 38 and thereby shift the 2!! switch operating arm.54 solas to open the motor, I

I circuit and thus stop the hoist drum; I

Each skip car rides on four wheels; the front. 1

two wheels 55 being single treadwheels, and F j the rear wheels 56 having double'treads, as shown :80 in Figure 3. In riding up the incline, the inner I rear wheels ride the rails-l8 until the skip car reaches the furnace top, Where the outer tread 1 portions of the rear wheels engage suitable dump 1 rails'which tilt the'rear of the car and thus 'discharge the contents into the furnace'hopper, this being the position indi'cated'at the top of Figure l. The'pipes 36 areslidably supported by the brackets 48 midwa'y between the two sets p, of'skip tracks.

midway between'the normal path of travel of the 1 cars and are so disposed as to be capable of being 1 moved by the rear wheels L58 of either skip car when the car is derailed. The skip cars-are normally prevented from derailingon the outer side l of the skipwa'ybridge-by continuous bumper rails 1 5'! (Figure 3) normally installed as part of theskipway bridge structure. However, due'to clear Y 1 ance requirements between skipcars it is not 1 1 practical to install a bumper to prevent skip cars 1 from derailing inwardly. Thus the present in- 1 vention provides means for preventing damage 1 to the skipway structure or to the furnace proper, in theevent of skip car derailment due to the skip car accidentally jumping the track inwardly or in a direction where thereis no bumper'rail to prevent such derailment. 1

From the foregoing; it is apparent that when either the skip car moving up or the one i'n'oving Thus the' 'flanges 38 are located- 1 down the'incline starts to derail, one of the rear wheels will strike one of the flanges 38 carried by one of the pipe sections-36. The car wheel will, move the pipe 36 up or down, depending upon 7 whether the derailed car is traveling up or down the incline. Movement of the pipe 36 will transmit motion to the arm 54 of the limit switch 34, 1

thereby'cutting off power to the hoist motor and stopping both skip cars, thus preventing damage to either thebridge or thefurnace.

While. I have described a preferred ,installa-' madeby those skilled in the art-without departure from the invention as defined in the appendcediclaims,

In'an apparatus for charging a blast furnace, an inclined skipway extending from a filling' station to the top of the furnace, a skip car running'on, rails carried by theskipway, a cable and, hoist drum for propelling .the skip car, a motor for driving the drum, a circuit including a switch tocontrola the operation of said-motor, 1 a plurality-of members located along'the line of travel of the skip car, said members being positioned to normally clear the moving skip car,

shiftable, means common to all of saidmembers adapted to be moved when, any of said members is struck by a derailed skip car, and a connection between said means and said switch whereby, upon derailment of theskipcar, said motor is automatically stopped. i '2. In anapparatus for charging a blast fur- I nace, an inclined skipway extending from afilling station to the top 'of the furnace, a skip car running 'on rails carried by the skipway, a cable and hoist drum for propelling the skip carja plurality of elongated elements having coupling con- 1 nections attheir contiguous ends, a plurality of bearings islidably supporting said elements, said couplings including flanges normally positioned in juxtaposition to the path of travel-0f the skip car inlocations to normally clear the moving car, one of said elements having an operative connection with a switch, and yielding means normall holding said elements in such positionthat said switch is maintained normally in closed circuit position, the parts being so constructed and arranged that upon derailment of the skip 

